CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Cash flows from operating activities:
Net (loss) income	$ (18,104)	$ 6,245
Adjustments to reconcile net income to net cash from operating activities:
Effect of change in revenue recognition	(17,382)	0
Depreciation	4,981	3,934
Amortization of intangible assets	769	758
Amortization of deferred financing costs	752	135
Amortization of discount on notes receivable	0	(148)
Non cash lease expenses	714	0
Loss of fixed asset disposal	318	0
Impairment of intangible assets	1,258	0
Share-based compensation	9,199	13,311
Change in deferred income taxes	0	(1,558)
Increase (decrease) in cash resulting from changes in:
Inventory	3,952	(4,592)
Prepaid expenses	4,778	(410)
Income tax receivable	(389)	212
Other current assets	(3,515)	855
Accounts payable	(5,444)	3,518
Accrued compensation	(1,948)	(3,832)
Accrued expenses	5,596	14,934
Other liabilities	(1,825)	900
Net cash flows (used in) provided by operating activities	(16,290)	34,262
Cash flows from investing activities:
Purchases of equipment	(1,055)	(7,590)
Proceeds from sale of property and equipment	0	30
Principal payments from note receivable	2,722	0
Patent application costs	(370)	(474)
Net cash flows provided by (used in) investing activities	1,297	(8,034)
Net Cash Provided by (Used in) Financing Activities [Abstract]
Proceeds from exercise of stock options	108	3,554
Stock repurchase under repurchase plan	0	(7,572)
Stock repurchased for tax withholdings on vesting of restricted stock	(1,283)	(4,629)
Deferred financing cost	(6,640)	0
Proceeds from term loan	72,750	0
Repayment of term loan	(938)	0
Payment under capital lease obligations		(2)
Net cash flows provided by (used in) financing activities	63,997	(8,649)
Net change in cash	49,004	17,579
Cash and cash equivalents, beginning of period	45,118	27,476
Cash and cash equivalents, end of period	$ 94,122	$ 45,055